1. Field of the Invention
The present invention relates to an apparatus for feeding an electric-component tape which includes a carrier tape and holds a plurality of electric components (e.g., electronic components), and a method of supplying a plurality of electric components from an electric-component tape, and in particular to the art of improving the efficiency of supplying of electric components.
2. Related Art Statement
There is known an electric-component ("EC") tape which includes a carrier tape having a plurality of feed holes arranged in a lengthwise direction thereof, and which holds a plurality of electric components ("ECs") at a predetermined pitch in the lengthwise direction. A feeding device which feeds the electric-component tape is disclosed in, e.g., U.S. Pat. No. 5,588,614. The disclosed feeding device includes a sprocket, a ratchet wheel, a ratchet pawl, and a pivotable member which supports the ratchet pawl. The sprocket is rotatable about an axis line perpendicular to the direction of feeding of the EC tape, and the ratchet wheel is rotatable with the sprocket, i.e., is not rotatable relative to the sprocket. The pivotable member is pivotable about the axis line of rotation of the sprocket, relative to the sprocket and the ratchet wheel, and the ratchet pawl is supported by the pivotable member such that the ratchet pawl is engageable with the teeth of the ratchet wheel.
When the pivotable member is pivoted forward because of the drive force of a drive source, the ratchet pawl is moved while being engaged with the teeth of the ratchet wheel, so that the ratchet wheel is rotated and accordingly the sprocket is rotated. Thus, the EC tape is fed. This is an EC-tape feeding action of the pivotable member. On the other hand, when the pivotable member is pivoted backward, the ratchet pawl is moved over the teeth of the ratchet wheel, so that the ratchet wheel or the sprocket is not rotated and the EC tape is not fed. This is an EC-tape-feed preparing action of the pivotable member. Thus, the pivotable member alternately performs the EC-tape feeding action and the EC-tape-feed preparing action.
Here, the distance by which the EC tape is fed by a single EC-tape feeding action (i.e., a single forward pivotal motion) of the pivotable member is defined as a reference pitch. In the case where the feeding device commonly feeds a first EC tape which holds ECs at a pitch equal to the reference pitch, and a second EC tape which holds ECs at a pitch equal to the product of the reference pitch and a natural number, the first EC tape can be fed by a single feeding action of the pivotable member, but the feeding of the second EC tape needs a plurality of feeding actions of the pivotable member and a plurality of preparing actions of the same. The feeding device which commonly feeds different sorts of EC tapes which hold ECs at different pitches enjoys a higher cost performance than individual exclusive feeding devices which feed the different sorts of EC tapes, respectively. However, the feeding of an EC tape over the distance equal to the product of the reference pitch and a natural number needs a time equal to the product of the natural number and the sum of a time needed to perform a single feeding action and a time needed to perform a single preparing action. This leads to lowering the efficiency of supplying of ECs.